A witness at the Long Island murder trial of Martin Heidgen – charged with drunkenly plowing his truck into a limousine and decapitating a 7-year-old flower girl – said Heidgen chugged “Irish car bombs,” a mix of stout, whiskey and Irish créme liqueur, at a party before the accident.

Tracy Sodikoff said Heidgen was the life of a pre-crash party as he laughed and played the drinking game Beer Pong.

Heidgen, who had just come from drinking in a bar, had several beers and two Irish car bombs at the party, she said.

Another witness said he thought Heidgen was playing a deadly “game of chicken” as he barreled toward oncoming traffic on the wrong side of the parkway.

Joseph Caruso, 35, told the jury, “I realized my life was in danger” when he saw Heidgen speeding at him on the Meadowbrook Parkway on July 2, 2005.

Caruso called 911 and told cops the driver was “doing, like, 100 miles an hour and almost killed me and somebody else.”